CPE Ergonomic Interventions & Solutions 3 — Questions and Answers
Question 1: A vibration-dampening glove is selected as a control for hand-arm vibration. According to the hierarchy of controls, this solution is classified as:
- Elimination
- Engineering control
- Administrative control
- Personal protective equipment (Correct answer)
Correct answer: Personal protective equipment
Gloves are personal protective equipment (PPE), which sits at the lowest tier of the hierarchy of controls and should supplement, not replace, higher-level interventions.
Question 2: A task requires workers to exert 18 lbs of push force on a cart. NIOSH guidelines suggest acceptable initial forces for pushing are closest to which value for a mixed-gender workforce?
- 50 lbs initial force
- 35 lbs initial force
- 15 lbs initial force (Correct answer)
- 25 lbs initial force
Correct answer: 15 lbs initial force
Liberty Mutual / Snook tables indicate that for mixed-gender populations, acceptable initial push forces are approximately 15–18 lbs depending on frequency and distance, placing 18 lbs at or near the acceptable limit.
Question 3: An ergonomist is evaluating seating for a call center. Which seat pan feature is most critical for workers with varying thigh lengths?
- Seat pan depth adjustability (Correct answer)
- Seat color and fabric choice
- Armrest width
- Headrest height
Correct answer: Seat pan depth adjustability
Adjustable seat pan depth ensures proper thigh support without popliteal pressure for workers of different leg proportions.
Question 4: After installing a height-adjustable workstation, productivity drops because workers rarely use the adjustment. What is the most likely root cause and best corrective action?
- The equipment is defective; replace it under warranty
- Workers were not adequately trained on the benefits and mechanics of adjustment; provide training and reminders (Correct answer)
- The workstations are too expensive; downgrade to fixed-height tables
- Increase administrative penalties for not adjusting the workstation
Correct answer: Workers were not adequately trained on the benefits and mechanics of adjustment; provide training and reminders
Lack of training and organizational prompts is the most common reason adjustable furniture goes unused; targeted training and cues significantly increase utilization rates.
Question 5: Which intervention most effectively reduces contact stress on the palmar surface of the hand during a gripping task?
- Using a tool handle with a larger diameter and rounded, padded grip (Correct answer)
- Using a tool with a smaller, textured handle for better grip security
- Applying grip tape to the existing tool handle
- Recommending the worker wear cotton gloves
Correct answer: Using a tool handle with a larger diameter and rounded, padded grip
A larger-diameter, padded, and rounded handle distributes contact forces over a greater surface area, reducing pressure concentration on palmar tissues.
Question 6: A manufacturing plant wants to reduce lower back injuries from repetitive shoveling. Which intervention has the highest expected efficacy?
- Providing back belts to all shovelers
- Redesigning the shoveling tool with a bent-handle ergonomic design and reducing load per scoop (Correct answer)
- Training workers in proper lifting technique
- Rotating workers to different shoveling stations
Correct answer: Redesigning the shoveling tool with a bent-handle ergonomic design and reducing load per scoop
Redesigning the tool to reduce load per scoop and maintain a more neutral lumbar posture directly addresses the biomechanical root cause and is an engineering control, the most effective tier.
Question 7: When evaluating the effectiveness of an ergonomic intervention post-implementation, which metric provides the most direct evidence of injury risk reduction?
- Worker satisfaction survey scores
- Reduction in RULA or REBA scores at the redesigned workstation (Correct answer)
- Number of ergonomic training sessions conducted
- Decrease in equipment purchase cost
Correct answer: Reduction in RULA or REBA scores at the redesigned workstation
Pre- and post-intervention observational assessment scores (e.g., RULA, REBA) directly quantify changes in postural and force risk factors and are the most valid measure of biomechanical risk reduction.
CPE Ergonomic Interventions & Solutions 3
A vibration-dampening glove is selected as a control for hand-arm vibration.
According to the hierarchy of controls, this solution is classified as: